Long-term physiological and economic consequences of growth retardation in children and adolescents.

The application of a lifespan perspective in human biology in recent years has shown that a number of early environmental factors influencing human growth and development have long-term biological or psycho-social consequences. Human growth is characterized by prolonged infancy, an extended childhood phase and high rates of growth during the adolescent growth spurt. It is unlikely that these characteristics would have evolved without having advantages, and curtailments have the potential for disadvantage. The present paper examines the evidence for long-term physiological and economic consequences of growth retardation in children and adolescents. The emphasis is the biological and economic imperatives of survival, subsistence, reproduction and production rather than aspects of metabolic competence. Many of the consequences of growth retardation are determined by the direct effect on body size, but many other consequences arise from the conditions that cause the growth retardation. Catch up of retarded growth can occur, but does not usually do so because of the continued presence of the retarding agents. Basal metabolism and physical work capacity are usually commensurate with the size of the individual; mechanical efficiency of physical work is unchanged, but falls in activity levels may occur along with a reduction in the pace of activity. Growth retardation in childhood is associated with a higher disease and mortality risk in adulthood, with decreased productivity and employment and promotion prospects. Studies are showing that relative deprivation and the accumulation of socially patterned exposures are important in some societies. Height and growth retardation have proved invaluable in reflecting these factors, but the next generation of studies may require more discriminating indices.